KR101249135B1 - Catalyst, process for production of the same, and use of the same - Google Patents

Abstract

The present invention provides a catalyst that does not corrode in an acidic electrolyte or in a high potential, is excellent in durability, and has a high oxygen reduction ability. The catalyst of the present invention is tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, Contains at least one metal M and niobium selected from the group consisting of yttrium, ruthenium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium and nickel It characterized in that it comprises a metal carbon dioxide.

Description

Catalyst, its manufacturing method and its use {CATALYST, PROCESS FOR PRODUCTION OF THE SAME, AND USE OF THE SAME}

The present invention relates to a catalyst, a method for producing the same, and a use thereof.

Fuel cells are classified into various types according to the type of electrolyte and the type of electrode, and typical examples thereof include alkali type, phosphoric acid type, molten carbonate type, solid electrolyte type, and solid polymer type. Among them, solid polymer fuel cells that can operate at low temperatures (about -40 ° C) to about 120 ° C have attracted attention, and in recent years, development and practical use as a low pollution power source for automobiles have been advanced. As a use of the solid polymer fuel cell, a vehicle driving source and a stationary power supply have been considered, but long-term durability is required to be applied to these applications.

This polymer solid fuel cell is a type in which a polymer solid electrolyte is sandwiched between an anode and a cathode, fuel is supplied to the anode, oxygen or air is supplied to the cathode, and oxygen is reduced at the cathode to draw electricity. Hydrogen or methanol is mainly used for fuel.

Conventionally, in order to increase the reaction rate of a fuel cell and to increase the energy conversion efficiency of the fuel cell, a layer containing a catalyst (hereinafter referred to as a "fuel cell catalyst layer") on the cathode (air electrode) surface and the anode (fuel electrode) surface of the fuel cell. ) Was formed.

As this catalyst, generally a noble metal is used, and platinum which is stable at a high electric potential and has high activity among noble metals has been mainly used. However, since platinum has a high price and a limited amount of resources, development of a replaceable catalyst has been required.

Moreover, the precious metal used for the cathode surface may melt | dissolve under an acidic atmosphere, and there existed a problem that it was not suitable for the use which requires long-term durability. For this reason, there has been a strong demand for the development of a catalyst which does not corrode in an acidic atmosphere, has excellent durability, and has a high oxygen reduction ability.

As a catalyst to replace platinum, materials containing nonmetals such as carbon, nitrogen, and boron have been recently conceived. The material containing these nonmetals is cheaper compared to precious metals, such as platinum, and is rich in resource amount.

In Non-Patent Document 1, a ZrOxN compound based on zirconium has been reported to exhibit an oxygen reducing ability.

Patent Literature 1 discloses an oxygen reduction electrode material containing one or more nitrides selected from the group of elements of Groups 4, 5, and 14 of the long-period table as platinum replacement materials.

However, the material containing these nonmetals has a problem that practically sufficient oxygen reduction ability cannot be obtained as a catalyst.

In addition, Patent Literature 2 discloses a carbonitride which is mixed with carbides, oxides and nitrides and subjected to heat treatment at 500 to 1500 占 폚 in a vacuum, inert or non-oxidizing atmosphere.

However, the carbonitride oxide disclosed in patent document 2 is a thin film magnetic head ceramic substrate material, and using this carbonitride oxide as a catalyst is not examined.

In addition, although platinum is useful not only as the catalyst for fuel cells but also as a catalyst for exhaust gas treatment or a catalyst for organic synthesis, since platinum has a high price and a limited amount of resources, it is possible to develop a catalyst that can be replaced in these applications. Was being asked.

Japanese Patent Laid-Open No. 2007-31781 Japanese Patent Application Laid-Open No. 2003-342058

S.Doi, A.Ishihara, S.Mitsushima, N.kamiya, and K.Ota, Journal of The Electrochemical Society, 2007, 154 (3) B362-B369

The present invention has been made to solve such problems in the prior art, and an object of the present invention is to provide a catalyst which does not corrode in an acidic electrolyte or a high potential, has excellent durability, and has a high oxygen reduction ability. have.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the problem of the said prior art, the catalyst containing the metal carbonitride containing a specific metal and niobium does not corrode in an acidic electrolyte or a high potential, it is excellent in durability, and has high oxygen It discovered that it had a reducing ability and came to complete this invention.

This invention relates to the following (1)-(21), for example.

(One)

Tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, yttrium, ruthenium, lanthanum, At least one metal selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and nickel (hereinafter referred to as "metal M" or "M" And metal carbonitrides containing niobium.

(2)

The composition formula of the metal carbonitride oxide is Nb _a M _b C _x N _y O _z (where a, b, x, y, z represent the ratio of the number of atoms, and 0.01≤a <1, 0 <b≤0.99, 0.01 ≤ x ≤ 2, 0.01 ≤ y ≤ 2, 0.01 ≤ z ≤ 3, a + b = 1, and x + y + z ≤ 5).

(3)

When the metal carbonitride is measured by powder X-ray diffraction (Cu-Kα), two or more diffraction line peaks are observed between diffraction angles 2θ = 33 ° to 43 ° (1) or The catalyst as described in (2).

(4)

The metal carbonitride is a mixture containing several phases, and peaks derived from Nb ₁₂ O ₂₉ are observed when the metal carbonitride is measured by powder X-ray diffraction (Cu-Kα-ray). The catalyst according to any one of (1) to (3).

(5)

Tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, yttrium, ruthenium, lanthanum, A mixture of oxides, niobium oxides and carbons of at least one metal M selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and nickel A step (ia) of obtaining a metal carbonitride by heat treatment in a nitrogen atmosphere or an inert gas containing nitrogen, and a step (ii) of obtaining a catalyst containing a metal carbonitride by heat treating the metal carbonitride in an oxygen-containing inert gas. Method for producing a catalyst comprising a metal carbonitride, characterized in that.

(6)

Tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, yttrium, ruthenium, lanthanum, A mixture of oxides, niobium carbide and niobium nitride of at least one metal M selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium and nickel And (ii) obtaining a metal carbonitride by heat-treating it in an inert gas, and (ii) obtaining a catalyst containing metal carbonitride by heat-treating the metal carbonitride in an oxygen-containing inert gas. Process for producing a catalyst comprising carbonitrides.

(7)

Tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, yttrium, ruthenium, lanthanum, Oxides, niobium carbide, niobium nitride and oxides of at least one metal M selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium and nickel And (ii) obtaining a metal carbonitride by heat-treating the mixture of niobium in an inert gas, and (ii) obtaining a catalyst containing metal carbonitride by heat-treating the metal carbonitride in an oxygen-containing inert gas. A method for producing a catalyst containing a metal carbonitride.

(8)

Tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, yttrium, ruthenium, lanthanum, Compounds containing at least one metal M, niobium carbide and niobium nitride selected from the group consisting of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium and nickel And (ii) obtaining a metal carbonitride by heat-treating the mixture in an inert gas, and (ii) obtaining a catalyst containing metal carbonitride by heat treating the metal carbonitride in an oxygen-containing inert gas. A method for producing a catalyst comprising a metal carbonitride.

(9)

The heat treatment temperature in the said process (ia) is the range of 600-1800 degreeC, The manufacturing method as described in (5) characterized by the above-mentioned.

(10)

The heat treatment temperature in the said process (ib) is the range of 600-1800 degreeC, The manufacturing method as described in (6) characterized by the above-mentioned.

(11)

The heat treatment temperature in the said process (ic) is the range of 600-1800 degreeC, The manufacturing method as described in (7) characterized by the above-mentioned.

(12)

The heat treatment temperature in the said process (id) is the range of 600-1800 degreeC, The manufacturing method as described in (8) characterized by the above-mentioned.

(13)

The heat treatment temperature in the said process (ii) is the range of 400-1400 degreeC, The manufacturing method in any one of (5)-(12) characterized by the above-mentioned.

(14)

Oxygen gas concentration in the inert gas in the said process (ii) is 0.1-10 volume% of range, The manufacturing method in any one of (5)-(13) characterized by the above-mentioned.

(15)

The inert gas in the said process (ii) contains hydrogen gas in 5 volume% or less of range, The manufacturing method in any one of (5)-(14) characterized by the above-mentioned.

(16)

The catalyst layer for fuel cells containing the catalyst in any one of (1)-(4).

(17)

The catalyst layer for a fuel cell according to (16), further comprising electron conductive particles.

(18)

An electrode having a fuel cell catalyst layer and a porous support layer, wherein the fuel cell catalyst layer is a fuel cell catalyst layer according to (16) or (17).

(19)

A membrane electrode assembly having a cathode, an anode, and an electrolyte membrane disposed between the cathode and the anode, wherein the cathode and / or the anode are the electrodes described in (18).

(20)

A fuel cell comprising the membrane electrode assembly according to (19).

(21)

A polymer electrolyte fuel cell comprising the membrane electrode assembly according to (19).

The catalyst of the present invention does not corrode in an acidic electrolyte or in a high potential, is stable, has a high oxygen reducing ability, and is inexpensive compared with platinum. Therefore, the fuel cell with the catalyst is relatively inexpensive and excellent in performance.

1 is a powder X-ray diffraction spectrum of the catalyst (1) of Example 1. FIG.
2 is a powder X-ray diffraction spectrum of the catalyst (2) of Example 2. FIG.
3 is a powder X-ray diffraction spectrum of the catalyst (3) of Example 3. FIG.
4 is a powder X-ray diffraction spectrum of the catalyst (4) of Example 4. FIG.
5 is a powder X-ray diffraction spectrum of the catalyst (5) of Example 5. FIG.
6 is a powder X-ray diffraction spectrum of the catalyst (6) of Example 6. FIG.
7 is a powder X-ray diffraction spectrum of the catalyst (7) of Example 7. FIG.
8 is a powder X-ray diffraction spectrum of the catalyst (8) of Example 8. FIG.
9 is a powder X-ray diffraction spectrum of the catalyst (9) of Example 9. FIG.
10 is a powder X-ray diffraction spectrum of the catalyst 10 of Example 10. FIG.
11 is a powder X-ray diffraction spectrum of the catalyst (11) of Example 11. FIG.
12 is a powder X-ray diffraction spectrum of the catalyst (13) of Example 12. FIG.
13 is a powder X-ray diffraction spectrum of the catalyst 14 of Example 13. FIG.
14 is a diagram of peak analysis of powder X-ray diffraction spectrum of catalyst 14 of Example 13. FIG.
15 is a powder X-ray diffraction spectrum of the catalyst (15) of Example 14. FIG.
16 is a diagram of peak analysis from powder X-ray diffraction spectrum of catalyst (15) of Example 14. FIG.
17 is a powder X-ray diffraction spectrum of the catalyst 16 of Example 15. FIG.
FIG. 18 is a diagram of peak analysis of powder X-ray diffraction spectrum of catalyst 16 of Example 15. FIG.
19 is a powder X-ray diffraction spectrum of the catalyst 17 of Example 16. FIG.
Fig. 20 shows the peak analysis of the powder X-ray diffraction spectrum of the catalyst 17 of Example 16.
21 is a powder X-ray diffraction spectrum of the catalyst 18 of Example 17. FIG.
Fig. 22 shows the peak analysis of the powder X-ray diffraction spectrum of the catalyst 18 of Example 17.
23 is a powder X-ray diffraction spectrum of the catalyst 19 of Example 18. FIG.
24 is a powder X-ray diffraction spectrum of the catalyst 20 of Example 19. FIG.
25 is a powder X-ray diffraction spectrum of the catalyst 21 of Example 20. FIG.
FIG. 26 is an enlarged view of the diffraction angle 2θ = 30 ° to 45 ° in the powder X-ray diffraction spectrum of the catalyst 21 of Example 20. FIG.
27 is a powder X-ray diffraction spectrum of the catalyst 22 of Example 21.
FIG. 28 is an enlarged view of the diffraction angle 2θ = 30 ° to 45 ° in the powder X-ray diffraction spectrum of the catalyst 22 of Example 21. FIG.
29 is a powder X-ray diffraction spectrum of the catalyst 23 of Example 22. FIG.
30 is an enlarged view of the diffraction angle 2θ = 30 ° to 45 ° in the powder X-ray diffraction spectrum of the catalyst 23 of Example 22. FIG.
31 is a powder X-ray diffraction spectrum of the catalyst 24 of Example 23. FIG.
32 is an enlarged view of the diffraction angle 2θ = 30 ° to 45 ° in the powder X-ray diffraction spectrum of the catalyst 24 of Example 23. FIG.
33 is a powder X-ray diffraction spectrum of the catalyst 25 of Example 24. FIG.
Fig. 34 is an enlarged view of the diffraction angle 2θ = 30 ° to 45 ° in the powder X-ray diffraction spectrum of the catalyst 25 of Example 24.
35 is a powder X-ray diffraction spectrum of the catalyst 26 of Example 25.
36 is an enlarged view of the diffraction angle 2θ = 30 ° to 45 ° in the powder X-ray diffraction spectrum of the catalyst 26 of Example 25. FIG.
37 is a powder X-ray diffraction spectrum of the catalyst 27 of Example 26. FIG.
FIG. 38 is an enlarged view of the diffraction angle 2θ = 30 ° to 45 ° in the powder X-ray diffraction spectrum of the catalyst 27 of Example 26. FIG.
39 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 1 of Example 1. FIG.
40 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 2 of Example 2. FIG.
FIG. 41 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 3 of Example 3. FIG.
42 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 4 of Example 4. FIG.
43 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 5 of Example 5. FIG.
44 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 6 of Example 6. FIG.
45 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 7 of Example 7. FIG.
46 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 8 of Example 8. FIG.
FIG. 47 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 9 of Example 9. FIG.
48 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 10 of Example 10. FIG.
FIG. 49 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 11 of Example 11. FIG.
50 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 12 of Comparative Example 1. FIG.
FIG. 51 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 13 of Example 12. FIG.
52 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 14 of Example 13. FIG.
FIG. 53 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 15 of Example 14. FIG.
54 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 16 of Example 15. FIG.
55 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 17 of Example 16. FIG.
56 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 18 of Example 17. FIG.
57 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 19 of Example 18. FIG.
58 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 20 of Example 19. FIG.
59 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 21 of Example 20. FIG.
FIG. 60 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 22 of Example 21. FIG.
61 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 23 of Example 22. FIG.
62 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 24 of Example 23. FIG.
FIG. 63 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 25 of Example 24. FIG.
64 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 26 of Example 25. FIG.
65 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 27 of Example 26. FIG.
66 is a graph evaluating the oxygen reduction ability of the fuel cell electrode 28 of Comparative Example 2. FIG.
67 is a graph evaluating the oxygen reduction capacity of the fuel cell electrode 29 of Comparative Example 3. FIG.

<Catalyst>

The catalyst of the present invention is tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, yttrium At least one metal M and niobium selected from the group consisting of ruthenium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium and nickel It is characterized by containing a metal carbonitride.

In addition, the composition formula of the metal carbonitride oxide is Nb _a M _b C _x N _y O _z (where a, b, x, y, z represents the ratio of the number of atoms, 0.01≤a <1, 0 <b≤0.99 , 0.01 ≦ x ≦ 2, 0.01 ≦ y ≦ 2, 0.01 ≦ z ≦ 3, a + b = 1, and x + y + z ≦ 5).

In the above composition formula, 0.05≤a≤0.99, 0.01≤b≤0.95 (more preferably 0.50≤a≤0.99, 0.01≤b≤0.50, still more preferably 0.80≤a≤0.99, 0.01≤b≤0.20), It is preferable that 0.01≤x≤2, 0.01≤y≤2, 0.05≤z≤3, and 0.07≤x + y + z≤5.

If the ratio of each atom number is the said range, since there exists a tendency for oxygen reduction potential to become high, it is preferable.

In the present invention, when the metal M is platinum, the amount of platinum, which is high in price and limited in resource amount, is suppressed, so that _{b in} the composition formula (Nb _a M _b C _x N _y O _z ) is It is 0.50 or less, Preferably it is 0.20 or less.

In the present invention, the "metal carbonitride oxide containing metal M and niobium" means a compound represented by Nb _a M _b C _x N _y O _z , or an oxide of metal M, carbide of metal M, metal M Nitride, Nitride of Metal M, Carbon of Metal M, Nitride of Metal M, Niobium, Oxide of Niobium, Carbide of Niobium, Nitride of Niobium, Carbonitride of Niobium, Carbonate of Niobium, Nitride of Niobium, Metal M and Niobium Oxides containing metals, carbides containing metal M and niobium, nitrides containing metal M and niobium, carbonitrides containing metal M and niobium, carbides containing metal M and niobium, containing metal M and niobium A mixture containing nitric oxide and the like, the composition of which is represented by Nb _a M _b C _x N _y O _z as _a whole (but may or may not contain a compound represented by Nb _a M _b C _x N _y O _z ), Or both. Of these, if it contains a niobium oxide such as Nb ₁₂ O ₂₉ having oxygen defects, it is preferred there is a tendency that higher oxygen reduction potential of the resulting catalyst.

In addition, when the said compound is measured by the powder X-ray diffraction method (Cu-K (alpha)), it is preferable that 2 or more diffraction line peaks are observed between diffraction angles 2 (theta) = 33 degrees-43 degrees. When two or more diffraction line peaks are observed, it is preferable at the point which the oxygen reduction potential of the catalyst obtained tends to become high.

The diffraction line peak refers to a peak obtained at a specific diffraction angle and diffraction intensity when the sample (crystalline) is irradiated with X-rays at various angles. In the present invention, a signal capable of detecting the ratio S / N of the signal S and the noise N to two or more is regarded as one diffraction line peak. Here, the noise N was taken as the width of the baseline.

As a measuring apparatus of the X-ray diffraction method, for example, a powder X-ray analyzer: Rigaku RAD-RX can be used, and as the measuring conditions, X-ray output (Cu-Kα): 50 kV, 180 mA, scanning axis : θ / 2θ, Measurement range (2θ): 10 ° to 89.98 °, Measurement mode: FT, Scanning width: 0.02 °, Sampling time: 0.70 sec, DS, SS, RS: 0.5 °, 0.5 °, 0.15 mm, Cygnus 5 meters radius: 185 mm.

Further, a mixture of the metal shot oxynitride contains several phase, the powder X-ray time by diffraction method (Cu-Kα ray) was measured for the metal-carbon oxynitride, it is preferable that the Nb ₁₂ O _29-derived peak observed Do. In addition, peaks derived from oxides such as NbO, NbO ₂ , Nb ₂ O ₅ , Nb ₂₅ O ₆₂ , Nb ₄₇ O ₁₁₆ , and Nb ₂₂ O ₅₄ may be observed.

The metal structure of the carbon nitrogen oxides include, but are not apparent, while the metallic carbon oxynitride, such as Nb ₁₂ O ₂₉ having oxygen defects is considered to exist consisting of a different oxide. Usually, Nb ₁₂ O ₂₉ alone does not express high oxygen reduction ability, but since the metal carbonitride has a phase in which Nb ₁₂ O ₂₉ or the like having an oxygen defect is present, the finally obtained catalyst has high oxygen reduction ability. The present inventors presume.

In the metal carbon oxide, when Nb ₁₂ O ₂₉ having an oxygen defect is used as one unit, it is considered that oxygen is bridged in the bridge configuration (Nb-OO-Nb) between Nb and Nb of each unit. Although the mechanism of expression of oxygen reduction ability is not clear, it is presumed that Nb contributing to the bridge coordination (Nb-OO-Nb) becomes the active point and the oxygen reduction ability is expressed. When Nb ₁₂ O ₂₉ having an oxygen defect overlaps in each unit, the bonding distance between Nb and Nb between the units becomes short. It is thought that the oxygen reduction ability improves, so that the part with a short said bond distance increases. In addition, it is presumed that, by intervening carbon or nitrogen in this unit, the electron density around Nb changes to improve the catalytic activity. In addition, it can be estimated that the electron conductivity is improved by intervening carbon and nitrogen, but the reason for the performance improvement is not clear.

The oxygen reduction initiation potential measured according to the following measuring method (A) of the catalyst used in the present invention is preferably 0.5 V (vs. NHE) or more based on the reversible hydrogen electrode.

[Measurement Method (A):

The catalyst and carbon are placed in a solvent and stirred by ultrasonic waves to obtain a suspension so that the catalyst dispersed in carbon, which is electron conductive particles, is 1% by mass. In addition, as a carbon source, carbon black (specific surface area: 100-300 m <2> / g) (for example, XC-72 by Cabot Corporation) is used, and it disperse | distributes so that a catalyst and carbon may be 95: 5 by mass ratio. In addition, isopropyl alcohol: water (mass ratio) = 2: 1 is used as a solvent.

30 microliters are extract | collected, adding an ultrasonic wave, it is dripped rapidly on a glass carbon electrode (diameter: 5.2 mm), and it is made to dry at 120 degreeC for 1 hour. By drying, the catalyst layer for fuel cells containing a catalyst is formed on a glass carbon electrode.

Subsequently, 10 μl of Nafion (Dupont's 5% Nafion solution (DE521)) diluted 10-fold with pure water is further added dropwise onto the fuel cell catalyst layer. It is dried at 120 ° C. for 1 hour.

By using the electrode thus obtained, a reversible hydrogen electrode in a sulfuric acid solution having the same concentration in a sulfuric acid solution of 0.5 mol / dm 3 in a sulfuric acid solution of 0.5 mol / dm 3 in an oxygen atmosphere and a nitrogen atmosphere is referred to as a reference electrode, and 5 mV. The potential at which a difference of 0.2 μA / cm 2 or more starts to appear in the reduction current in the oxygen atmosphere and the reduction current in the nitrogen atmosphere when the current-potential curve is measured by polarizing at a potential scanning speed of / sec is referred to as the oxygen reduction start potential. ]

When the oxygen reduction start potential is less than 0.7 V (vs. NHE), hydrogen peroxide may be generated when the catalyst is used as a catalyst for a cathode of a fuel cell. In addition, the oxygen reduction initiation potential is preferably 0.85 V (vs. NHE) or more, since oxygen is appropriately reduced. In addition, the higher the oxygen reduction initiation potential is preferable, and there is no particular upper limit, but the upper limit of the oxygen reduction initiation potential is 1.23 V (vs. NHE), which is a theoretical value.

The catalyst layer for fuel cells of the present invention formed using the catalyst is preferably used at an electric potential of 0.4 V (vs. NHE) or higher in an acidic electrolyte, and the upper limit of the electric potential is determined by the stability of the electrode, where oxygen is generated. A potential of up to about 1.23 V (vs. NHE) can be used.

If the potential is less than 0.4 V (vs. NHE), there is no problem at all from the viewpoint of the stability of the compound, but oxygen cannot be properly reduced, and the usefulness of the membrane electrode assembly included in the fuel cell as a fuel cell catalyst layer is insufficient. .

<Method for Preparing Catalyst>

The method for producing the catalyst is not particularly limited, but for example, tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, At least 1 selected from the group consisting of gold, silver, iridium, palladium, yttrium, ruthenium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium and nickel Metal carbonitrides containing the species of metal M and niobium are heat-treated in an inert gas containing oxygen, thereby forming tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, Cobalt, manganese, cerium, mercury, plutonium, gold, silver, iridium, palladium, yttrium, ruthenium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium And a process for obtaining a metal carbonitride containing at least one metal M and niobium selected from the group consisting of europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium and nickel. have.

As a method of obtaining the said metal carbonitride used for the said process, the metal carbonitride is manufactured by heat-processing the mixture of the oxide of metal M, niobium oxide, and carbon in nitrogen atmosphere or inert gas containing nitrogen (I) ), A method of producing metal carbonitride by heat-treating a mixture of the oxide of metal M, niobium carbide and niobium nitride in an inert gas such as nitrogen gas, or the oxide of metal M, niobium carbide, niobium nitride and Method (III) for producing a metal carbonitride by heat-treating a mixture of niobium oxide in an inert gas such as nitrogen gas, or a compound containing the metal M (for example, an organic acid salt, chloride, carbide, nitride, complex, etc.) , Niobium carbide and niobium nitride mixture by heat-treating in an inert gas such as nitrogen gas A and a method for producing (IV). Moreover, as long as the said metal carbonitride can be obtained, it will not specifically limit as a raw material, For example, the raw material in the said manufacturing methods (I)-(IV), and other raw materials can be used in combination. The method (V) which manufactures a metal carbonitride by heat-processing the mixture thus combined in inert gas, such as nitrogen gas, may be sufficient.

[Manufacturing Method (I)]

The manufacturing method (I) is a method of manufacturing metal carbonitride by heat-treating the mixture of the said oxide of metal M, niobium oxide, and carbon in nitrogen atmosphere or inert gas containing nitrogen.

The heat treatment temperature at the time of producing a metal carbonitride is the range of 600 degreeC-1800 degreeC, Preferably it is the range of 800-1600 degreeC. If the said heat processing temperature is in the said range, it is preferable at the point which crystallinity and uniformity are favorable. If the said heat treatment temperature is less than 600 degreeC, crystallinity will be bad, and there exists a tendency for uniformity to worsen, and if it is 1800 degreeC or more, it will tend to become easy to sinter.

The oxides of the metal M of the raw material are tin oxide, indium oxide, platinum oxide, tantalum oxide, zirconium oxide, copper oxide, iron oxide, tungsten oxide, chromium oxide, molybdenum oxide, hafnium oxide, titanium oxide, vanadium oxide, cobalt oxide, and oxide Manganese, cerium oxide, mercury oxide, plutonium oxide, gold oxide, silver oxide, iridium oxide, palladium oxide, yttrium oxide, ruthenium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, promethium oxide, samarium oxide, europium oxide, gadolinium oxide , Terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, tulium oxide, ytterbium oxide, lutetium oxide, nickel oxide and the like. One or more types of oxides of the metal M can be used.

As a niobium oxide of the starting materials, and the like NbO, NbO ₂ and Nb ₂ O _5.

Examples of the carbon of the raw material include carbon, carbon black, graphite, graphite, activated carbon, carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes. If the particle diameter of the carbon powder is further smaller, the specific surface area becomes large, and thus it is preferable to react with the oxide, which is preferable. For example, carbon black (specific surface area: 100-300 m <2> / g, for example XC-72 by Cabot Corporation) etc. is used suitably.

Even if any of the above raw materials are used, the catalyst containing the metal carbonitride obtained by heat-treating the metal carbonitride obtained from the oxide, niobium oxide and carbon of the metal M in an inert gas containing oxygen has a high oxygen reduction initiation potential and is active. This is high.

By controlling the compounding amount (molar ratio) of the oxide, niobium oxide, and carbon of the metal M, an appropriate metal carbonitride can be obtained.

The said compounding quantity (molar ratio) is 0.01-10 mol of oxides of the said metal M, and 1-10 mol of carbons normally with respect to 1 mol of niobium oxides, Preferably, it is an oxide of said metal M with respect to 1 mol of niobium oxides 0.01-4 mol of this and 2-6 mol of carbon. When the metal carbonitride made from the compounding molar ratio which satisfy | fills the said range is used, it exists in the tendency to obtain the metal carbonitride which has high oxygen reduction initiation potential and high activity.

[Manufacturing Method (II)]

Manufacturing method (II) is a method of manufacturing metal carbonitride by heat-processing the mixture of the said oxide of metal M, niobium carbide, and niobium nitride in inert gas, such as nitrogen gas.

The heat treatment temperature at the time of producing a metal carbonitride is the range of 600 degreeC-1800 degreeC, Preferably it is the range of 800-1600 degreeC. If the said heat processing temperature is in the said range, it is preferable at the point which crystallinity and uniformity are favorable. If the said heat treatment temperature is less than 600 degreeC, crystallinity will be bad, and there exists a tendency for uniformity to worsen, and if it is 1800 degreeC or more, it will tend to become easy to sinter.

As the raw material, oxides of the metal M, niobium carbide and niobium nitride are used.

The oxides of the metal M of the raw material are tin oxide, indium oxide, platinum oxide, tantalum oxide, zirconium oxide, copper oxide, iron oxide, tungsten oxide, chromium oxide, molybdenum oxide, hafnium oxide, titanium oxide, vanadium oxide, cobalt oxide, and oxide Manganese, cerium oxide, mercury oxide, plutonium oxide, gold oxide, silver oxide, iridium oxide, palladium oxide, yttrium oxide, ruthenium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, promethium oxide, samarium oxide, europium oxide, gadolinium oxide , Terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, tulium oxide, ytterbium oxide, lutetium oxide, nickel oxide and the like. One or more types of oxides of the metal M can be used.

As niobium carbide of a raw material, NbC etc. are mentioned.

As niobium nitride as a raw material, NbN etc. are mentioned.

Even if any of the above raw materials are used, the catalyst containing the metal carbonitride obtained by heat-treating the metal carbonitride obtained from the oxide of metal M, niobium carbide and niobium nitride in an inert gas containing oxygen, has a high oxygen reduction initiation potential, High activity

Proper metal carbonitride can be obtained by controlling the compounding amount (molar ratio) of the said oxide of metal M, niobium carbide, and niobium nitride. The compounding amount (molar ratio) is usually 0.01 to 500 mol of niobium carbide (NbC) and 0.01 to 50 mol of oxide of the metal M, with respect to 1 mol of niobium nitride (NbN), preferably niobium nitride (NbN) Niobium carbide (NbC) is 0.1-300 mol with respect to 1 mol, and the oxide of the said metal M is 0.1-30 mol. When the metal carbonitride made from the compounding molar ratio which satisfy | fills the said range is used, it exists in the tendency to obtain the metal carbonitride which has high oxygen reduction initiation potential and high activity.

[Manufacturing Method (III)]

Manufacturing method (III) is a method of manufacturing metal carbonitride by heat-treating the mixture of the said oxide of metal M, niobium carbide, niobium nitride, and niobium oxide in inert gas, such as nitrogen gas.

The heat treatment temperature at the time of producing a metal carbonitride is the range of 600 degreeC-1800 degreeC, Preferably it is the range of 800-1600 degreeC. If the said heat processing temperature is in the said range, it is preferable at the point which crystallinity and uniformity are favorable. If the said heat treatment temperature is less than 600 degreeC, crystallinity will be bad, and there exists a tendency for uniformity to worsen, and if it is 1800 degreeC or more, it will tend to become easy to sinter.

As the raw material, oxides of the metal M, niobium carbide, niobium nitride, and niobium oxide are used.

The oxides of the metal M of the raw material are tin oxide, indium oxide, platinum oxide, tantalum oxide, zirconium oxide, copper oxide, iron oxide, tungsten oxide, chromium oxide, molybdenum oxide, hafnium oxide, titanium oxide, vanadium oxide, cobalt oxide, and oxide Manganese, cerium oxide, mercury oxide, plutonium oxide, gold oxide, silver oxide, iridium oxide, palladium oxide, yttrium oxide, ruthenium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, promethium oxide, samarium oxide, europium oxide, gadolinium oxide , Terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, tulium oxide, ytterbium oxide, lutetium oxide, nickel oxide and the like. One or more types of oxides of the metal M can be used.

As niobium carbide of a raw material, NbC etc. are mentioned.

As niobium nitride as a raw material, NbN etc. are mentioned.

As a niobium oxide of the starting materials, and the like NbO, NbO ₂ and Nb ₂ O _5.

Even if any of the above raw materials are used, the catalyst containing the metal carbonitride obtained by heat-treating the metal carbonitride obtained from the oxide, niobium carbide, niobium nitride and niobium oxide of the metal M in an inert gas containing oxygen is used for the oxygen reduction initiation potential. Is high and activity is high.

By controlling the compounding amount (molar ratio) of the oxide, niobium carbide, niobium nitride, and niobium oxide of the metal M, an appropriate metal carbonitride can be obtained. The compounding amount (molar ratio) is usually 0.01 to 500 mol of niobium carbide (NbC), 0.01 to 50 mol of the metal M oxide and niobium oxide, with respect to 1 mol of niobium nitride (NbN), preferably, Niobium carbide (NbC) is 0.1-300 mol with respect to 1 mol of niobium nitride (NbN), and 0.1-30 mol of oxides and niobium oxide of the said metal M together. When the metal carbonitride made from the compounding molar ratio which satisfy | fills the said range is used, it exists in the tendency to obtain the metal carbonitride which has high oxygen reduction initiation potential and high activity.

[Manufacturing Method (IV)]

Manufacturing method (IV) is a method of manufacturing metal carbonitride by heat-treating a mixture of the compound containing metal M, niobium carbide, and niobium nitride in an inert gas such as nitrogen gas.

The heat treatment temperature at the time of producing a metal carbonitride is the range of 600 degreeC-1800 degreeC, Preferably it is the range of 800-1600 degreeC. If the said heat processing temperature is in the said range, it is preferable at the point which crystallinity and uniformity are favorable. If the said heat treatment temperature is less than 600 degreeC, crystallinity will be bad, and there exists a tendency for uniformity to worsen, and if it is 1800 degreeC or more, it will tend to become easy to sinter.

As a raw material, the compound containing said metal M, niobium carbide, and niobium nitride are used.

Compounds containing metal M as a raw material include tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, Organic salts such as iridium, palladium, yttrium, ruthenium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium or nickel, carbonates, chlorides, organic complexes , Carbides, nitrides and the like. One type or more of compounds containing metal M can be used.

As niobium carbide of a raw material, NbC etc. are mentioned.

As niobium nitride as a raw material, NbN etc. are mentioned.

Even if any of the above raw materials are used, the catalyst containing the metal carbonitride obtained by heat-treating the metal carbonitride obtained from the compound containing metal M, niobium carbide and niobium nitride in an inert gas containing oxygen, has an oxygen reduction initiation potential. High, high activity.

By controlling the compounding amount (molar ratio) of the compound containing the metal M, niobium carbide and niobium nitride, an appropriate metal carbonitride can be obtained. The compounding amount (molar ratio) is usually 0.01 to 500 mol of niobium carbide (NbC) and 0.001 to 50 mol of the compound containing the metal M with respect to 1 mol of niobium nitride (NbN), and preferably niobium nitride Niobium carbide (NbC) is 0.1-300 mol with respect to 1 mol (NbN), and the compound containing the said metal M is 0.01-30 mol. When the metal carbonitride made from the compounding molar ratio which satisfy | fills the said range is used, it exists in the tendency to obtain the metal carbonitride which has high oxygen reduction initiation potential and high activity.

[Manufacturing Method (V)]

As long as the said metal carbonitride can be obtained, it will not specifically limit as a raw material, The raw material in the said manufacturing methods (I)-(IV), and other raw materials can be used in various combinations.

Manufacturing method (V) is a method of manufacturing metal carbonitride by heat-processing raw material mixtures other than the combination of the raw materials in said manufacturing methods (I)-(IV) in inert gas, such as nitrogen gas.

The heat treatment temperature at the time of producing a metal carbonitride is the range of 600 degreeC-1800 degreeC, Preferably it is the range of 800-1600 degreeC. If the said heat processing temperature is in the said range, it is preferable at the point which crystallinity and uniformity are favorable. If the said heat treatment temperature is less than 600 degreeC, crystallinity will be bad, and there exists a tendency for uniformity to worsen, and if it is 1800 degreeC or more, it will tend to become easy to sinter.

As a raw material, the mixture which variously combined the compound containing the said metal M, niobium carbide, niobium nitride, niobium oxide, niobium precursor, carbon, etc. can be used as a raw material mixture, for example.

Compounds containing metal M as a raw material include tin, indium, platinum, tantalum, zirconium, copper, iron, tungsten, chromium, molybdenum, hafnium, titanium, vanadium, cobalt, manganese, cerium, mercury, plutonium, gold, silver, Organic salts such as iridium, palladium, yttrium, ruthenium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, ruthetium or nickel, carbonates, chlorides, organic complexes , Carbides, nitrides, precursors and the like. One type or more of compounds containing metal M can be used.

As niobium carbide of a raw material, NbC etc. are mentioned.

As niobium nitride as a raw material, NbN etc. are mentioned.

As a niobium oxide of the starting materials, and the like NbO, NbO ₂ and Nb ₂ O _5.

Examples of niobium precursors include organic acid salts, carbonates, chlorides, organic complexes, carbides, nitrides, and alkoxy compounds of niobium.

Examples of the carbon of the raw material include carbon, carbon black, graphite, graphite, activated carbon, carbon nanotubes, carbon nanofibers, carbon nanohorns, and fullerenes. When the particle diameter of the carbon powder is smaller, the specific surface area becomes large and is preferable because it becomes easy to react with the oxide. For example, carbon black (specific surface area: 100-300 m <2> / g, for example XC-72 by Cabot Corporation) etc. is used suitably.

Even if any of the above raw materials are used, the catalyst containing the metal carbonitride obtained by heat-treating the metal carbonitride obtained in an inert gas containing oxygen has high oxygen reduction initiation potential and high activity.

For example, by controlling the compounding amount (molar ratio) of the compound containing metal M, niobium carbide and niobium nitride, an appropriate metal carbonitride can be obtained. The compounding amount (molar ratio) is usually 0.01 to 500 mol of niobium carbide (NbC) and 0.001 to 50 mol of the compound containing the metal M, with respect to 1 mol of niobium nitride (NbN), and preferably niobium nitride (NbN). ) 0.1 to 300 moles of niobium carbide (NbC) and 0.01 to 30 moles of the compound containing the metal M per 1 mole. When the metal carbonitride made from the compounding molar ratio which satisfy | fills the said range is used, it exists in the tendency to obtain the metal carbonitride which has high oxygen reduction initiation potential and high activity.

(Manufacturing process of metal carbonitride)

Next, the process of obtaining metal carbonitride oxide by heat-processing the metal carbonitride obtained by the said manufacturing methods (I)-(V) in oxygen containing inert gas is demonstrated.

Examples of the inert gas include nitrogen, helium gas, neon gas, argon gas, krypton gas, xenon gas or radon gas. Nitrogen, argon gas or helium gas is particularly preferable in view of relatively easy availability.

The concentration of the oxygen gas in the inert gas depends on the heat treatment time and the heat treatment temperature, but is preferably 0.1 to 10% by volume, particularly preferably 0.5 to 5% by volume. If the concentration of the oxygen gas is in the above range, it is preferable in that uniform carbonitride is formed. Moreover, when the concentration of the oxygen gas is less than 0.1% by volume, it tends to be in an unoxidized state, and when it exceeds 10% by volume, oxidation tends to proceed excessively.

It is preferable to contain hydrogen gas in the range of 5 volume% or less in the said inert gas. The hydrogen gas content is more preferably 0.01 to 4% by volume, still more preferably 0.1 to 4% by volume. In addition, the volume% in this invention is a value in a standard state.

The heat treatment temperature in this step is usually in the range of 400 to 1400 ° C, and preferably in the range of 600 to 1200 ° C. If the said heat processing temperature is in the said range, it is preferable at the point at which a uniform metal carbonitride is formed. If the heat treatment temperature is less than 400 ° C, oxidation tends not to proceed, and if it is 1400 ° C or more, oxidation tends to proceed excessively and crystal growth tends to occur.

As a heat processing method in the said process, the stationary method, the stirring method, the dropping method, the powder capture method, etc. are mentioned.

The dropping method means that a furnace is heated to a predetermined heat treatment temperature while flowing an inert gas containing a small amount of oxygen gas in an induction furnace, and the thermal equilibrium is maintained at the temperature, and then a metal is placed in a crucible which is a heating zone of the furnace. It is a method of dropping carbonitride and performing heat treatment. The dropping method is preferable in that aggregation and growth of particles of metal carbonitride can be suppressed to a minimum.

The powder capturing method is characterized in that metal carbonitrides are suspended as droplets in an inert gas atmosphere containing a small amount of oxygen gas, metal carbonitrides are trapped in a vertical tubular furnace maintained at a predetermined heat treatment temperature, and subjected to heat treatment. Way.

In the case of the dropping method, the heat treatment time of the metal carbonitride is usually 0.5 to 10 minutes, preferably 0.5 to 3 minutes. If the heat treatment time is in the above range, there is a tendency for a uniform metal carbonitride to be formed, which is preferable. If the heat treatment time is less than 0.5 minutes, the metal carbonitride oxide tends to be partially formed, and if it exceeds 10 minutes, the oxidation tends to proceed excessively.

In the case of the powder trapping method, the heat treatment time of the metal carbonitride is 0.2 second to 1 minute, preferably 0.2 to 10 seconds. If the heat treatment time is in the above range, there is a tendency for a uniform metal carbonitride to be formed, which is preferable. If the heat treatment time is less than 0.2 second, the metal carbonitride tends to be partially formed, and if it exceeds 1 minute, the oxidation tends to proceed excessively. When performing in a tubular furnace, the heat treatment time of a metal carbonitride is 0.1 to 10 hours, Preferably it is 0.5 to 5 hours. If the heat treatment time is in the above range, there is a tendency for a uniform metal carbonitride to be formed, which is preferable. If the heat treatment time is less than 0.1 hour, the metal carbonitride oxide tends to be partially formed, and if it exceeds 10 hours, the oxidation tends to proceed excessively.

As a catalyst of this invention, although the metal carbonitride obtained by the above-mentioned manufacturing method etc. may be used as it is, you may further disintegrate the metal carbonitride obtained, and may use what became finer powder.

As a method for disintegrating the metal carbonitride, for example, a roll rolling mill, a ball mill, a medium stirring mill, an air flow pulverizer, a mortar, a method by a crushing tank, etc. may be mentioned. In the point which can be made into a granule, the method by the airflow grinder is preferable, and the method by induction is preferable at the point which a small amount process becomes easy.

<Use>

The catalyst of the present invention can be used as an alternative to the platinum catalyst.

For example, it can be used as a catalyst for fuel cells, a catalyst for exhaust gas treatment, or a catalyst for organic synthesis.

The catalyst layer for fuel cells of the present invention is characterized by comprising the above catalyst.

The catalyst layer for fuel cells includes an anode catalyst layer and a cathode catalyst layer, but the catalyst can be used for both. Since the said catalyst is excellent in durability and large in oxygen reduction ability, it is preferable to use it for a cathode catalyst layer.

It is preferable that the catalyst layer for fuel cells of the present invention further contains electron conductive particles. When the catalyst layer for a fuel cell including the catalyst further includes electron conductive particles, the reduction current can be further increased. Since the electron conductive particles generate an electrical contact for causing an electrochemical reaction to the catalyst, it is considered to increase the reduction current.

The electron conductive particles are usually used as a carrier of the catalyst.

Examples of the material constituting the electron conductive particles include carbon, conductive polymers, conductive ceramics, metals or conductive inorganic oxides such as tungsten oxide or iridium oxide, and these may be used alone or in combination. In particular, carbon particles having a large specific surface area alone or mixtures of carbon particles having a large specific surface area with other electron conductive particles are preferable. That is, it is preferable that a catalyst layer for fuel cells contains the said catalyst and carbon particle with a large specific surface area.

As carbon, carbon black, graphite, graphite, activated carbon, carbon nanotubes, carbon nanofibers, carbon nanohorns, fullerenes and the like can be used. If the particle diameter of carbon is too small, it is difficult to form an electron conduction path, and if too large, the gas diffusivity of the catalyst layer for a fuel cell tends to be lowered or the utilization of the catalyst tends to be lowered. And it is more preferable that it is the range of 10-100 nm.

When the material constituting the electron conductive particles is carbon, the mass ratio (catalyst: electron conductive particles) of the catalyst and carbon is preferably 4: 1 to 1000: 1.

The conductive polymer is not particularly limited, but for example, polyacetylene, poly-p-phenylene, polyaniline, polyalkylaniline, polypyrrole, polythiophene, polyindole, poly-1, 5-diaminoanthraquinone, polyaminodi Phenyl, poly (o-phenylenediamine), poly (quinolinium) salt, polypyridine, polyquinoxaline, polyphenylquinoxaline and the like. Among these, polypyrrole, polyaniline and polythiophene are preferable, and polypyrrole is more preferable.

The polymer electrolyte is not particularly limited as long as it is generally used in a catalyst layer for fuel cells. Specifically, polymers doped with inorganic acids such as perfluorocarbon polymers having sulfonic acid groups (for example, Nafion [Dupont's 5% Nafion solution (DE521)), etc.), hydrocarbon-based high molecular compounds having sulfonic acid groups, and phosphoric acid And organic / inorganic hybrid polymers in which some of the compounds are substituted with proton conductive functional groups, and proton conductors in which the polymer matrix is impregnated with a phosphoric acid solution or a sulfuric acid solution. Among these, Nafion (Dupont's 5% Nafion solution (DE521)) is preferable.

The fuel cell catalyst layer of the present invention can be used anywhere in the anode catalyst layer or the cathode catalyst layer. Since the catalyst layer for fuel cells of the present invention has a high oxygen reduction ability and contains a catalyst which is hard to corrode even in a high electrolyte in an acidic electrolyte, it is useful as a catalyst layer (catalytic catalyst layer) formed on the cathode of a fuel cell. In particular, it is used suitably for the catalyst layer formed in the cathode of the membrane electrode assembly with which a solid polymer fuel cell is equipped.

As a method of disperse | distributing the said catalyst on the said electroconductive particle which is a support | carrier, methods, such as airflow dispersion and dispersion in a liquid, are mentioned. Dispersion in a liquid is preferable because the thing which disperse | distributed the catalyst and electron conductive particle in a solvent can be used for the catalyst layer formation process for fuel cells. As dispersion in a liquid, the method by orifice shrinkage flow, the method by rotational shear flow, the method by ultrasonic waves, etc. are mentioned. When dispersing in a liquid, the solvent used is not particularly limited as long as it can disperse without eroding the catalyst or the electron conductive particles, but a volatile liquid organic solvent or water is generally used.

Further, when the catalyst is dispersed on the electron conductive particles, the electrolyte and the dispersant may be dispersed at the same time.

Although there is no restriction | limiting in particular as a formation method of the fuel cell catalyst layer, For example, the method of apply | coating the suspension containing the said catalyst, electron conductive particle, and electrolyte to the electrolyte membrane or gas diffusion layer mentioned later is mentioned. Examples of the coating method include a dipping method, a screen printing method, a roll coating method, a spray method, and the like. Moreover, the method of forming a fuel cell catalyst layer in an electrolyte membrane by the transfer method after forming the catalyst layer for a fuel cell in a base material by the coating method or the filtration method is given the suspension containing the said catalyst, an electron conductive particle, and an electrolyte.

The electrode of this invention has the said fuel cell catalyst layer and a porous support layer, It is characterized by the above-mentioned.

The electrode of the present invention can be used for either the cathode or the anode. Since the electrode of this invention is excellent in durability and large in catalytic ability, when used for a cathode, it exhibits more effects.

A porous support layer is a layer which diffuses gas (henceforth a "gas diffusion layer"). As the gas diffusion layer, any material can be used as long as it has electron conductivity, high gas diffusivity, and high corrosion resistance, but is generally coated with carbon-based porous materials such as carbon paper and carbon cross, and stainless steel and corrosion resistant material for weight reduction. One aluminum foil is used.

The membrane electrode assembly of the present invention is a membrane electrode assembly having a cathode, an anode, and an electrolyte membrane disposed between the cathode and the anode, wherein the cathode and / or the anode are the electrode.

As the electrolyte membrane, for example, an electrolyte membrane or a hydrocarbon electrolyte membrane using a perfluorosulfonic acid type is generally used. However, a membrane in which the polymer microporous membrane is impregnated with a liquid electrolyte, or a membrane in which the polymer electrolyte is filled with a porous body is used. You may use it.

Moreover, the fuel cell of this invention is provided with the said membrane electrode assembly. It is characterized by the above-mentioned.

The electrode reaction of the fuel cell takes place at the so-called three-phase interface (electrolyte-electrode catalyst-reaction gas). Fuel cells are classified into several types according to differences in electrolytes and the like, and there are molten carbonate type (MCFC), phosphoric acid type (PAFC), solid oxide type (SOFC), and solid polymer type (PEFC). Among them, the membrane electrode assembly of the present invention is preferably used for a solid polymer fuel cell.

<Examples>

Although an Example demonstrates this invention further in detail below, this invention is not limited to these Examples.

In addition, various measurements in the Example and the comparative example were performed by the following method.

[Analysis method]

1. Powder X-ray diffraction

Powder X-ray diffraction of the sample was performed using the rotor flex by Rigaku Denki Co., Ltd. and X'Pert Pro by PANalytical.

The number of diffraction line peaks in the powder X-ray diffraction of each sample is determined by considering the signal capable of detecting the ratio (S / N) of the signal S and the noise N to two or more as one peak. It was. In addition, the noise N was made into the width of a baseline.

2. Elemental analysis

Carbon: About 0.1 g of the sample was measured and measured by Horiba Seisakusho EMIA-110.

Nitrogen and oxygen: About 0.1 g of a sample was measured, and it enclosed in Ni-Cup, and it measured by the ON analyzer.

Niobium and other metals M: Approximately 0.1 g of the sample was weighed into a platinum dish, and acid was added to decompose the mixture. This heated degradation product was fixed, diluted, and quantified by ICP-MS.

Example 1

1. Preparation of Catalyst

4.95 g (39.6 mmol) of niobium (IV) (NbO ₂ ) and 60 mg (0.4 mmol) of tin (IV) (SnO ₂ ) were sufficiently ground and mixed with 1.2 g (100 mmol) of carbon (Vulcan72, manufactured by Cabot). 4.23 g of carbonitrides (1) containing tin (1 mol%) and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1400 degreeC for 3 hours in nitrogen atmosphere.

1.02 g of the obtained carbonitride (1) was heat treated at 800 ° C. for 1 hour in an tubular furnace while argon gas containing 1% by volume of oxygen gas was used, and carbon dioxide containing tin (1 mol%) and niobium (Hereinafter also referred to as `` catalyst (1) '') 1.10g was obtained.

The powder X-ray diffraction spectrum of the catalyst (1) is shown in Fig. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

The oxygen reduction ability was measured as follows. 0.095 g of catalyst (1) and 0.005 g of carbon (XC-72 manufactured by Cabot) were added to 10 g of a mixed solution in a mass ratio of isopropyl alcohol: pure water = 2: 1, stirred with ultrasonic waves, suspended and mixed. 30 microliters of this mixture was apply | coated to the glass carbon electrode (made by Toka Carbon, diameter: 5.2 mm), and it dried at 120 degreeC for 1 hour. Further, 10 μl of a 10-fold diluted Nafion (Dupont's 5% Nafion solution (DE521)) to 10 times of pure water was applied, and dried at 120 ° C. for 1 hour to obtain a fuel cell electrode (1).

3. Evaluation of Oxygen Reduction Capacity

The catalytic performance (oxygen reduction capacity) of the fuel cell electrode 1 thus produced was evaluated by the following method.

First, the produced fuel cell electrode 1 was polarized in a sulfuric acid solution of 0.5 mol / dm 3 in an oxygen atmosphere and a nitrogen atmosphere at 30 ° C. at a potential scanning speed of 5 mV / sec, and a current-potential curve was measured. In that case, the reversible hydrogen electrode in the sulfuric acid solution of the same density | concentration was called the reference electrode.

From the measurement results, the potential at which a difference of 0.2 μA / cm 2 or more starts to appear in the reduction current in the oxygen atmosphere and the reduction current in the nitrogen atmosphere was called the oxygen reduction start potential, and the difference between them was called the oxygen reduction current.

The catalytic performance (oxygen reduction ability) of the fuel cell electrode 1 produced by this oxygen reduction start potential and oxygen reduction current was evaluated.

In other words, the higher the oxygen reduction initiation potential and the larger the oxygen reduction current, the higher the catalytic capability (oxygen reduction ability) of the fuel cell electrode 1.

39 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 1 produced in Example 1 had an oxygen reduction initiation potential of 0.78 V (vs. NHE) and had a high oxygen reduction ability.

[Example 2]

1. Preparation of Catalyst

4.75 g (38 mmol) of niobium (IV) (NbO ₂ ) and 302 mg ( ₂ mmol) of tin (IV) (SnO ₂ ) were sufficiently ground and mixed with 1.2 g (100 mmol) of carbon (Vulcan 72, manufactured by Cabot). 4.10 g of carbonitride (2) containing tin (5 mol%) and niobium was obtained by heat-processing this mixed powder in a tubular furnace at 1400 degreeC for 3 hours in nitrogen atmosphere.

Carbon containing tin (5 mol%) and niobium was obtained by heat-treating 1.02 g of the obtained carbonitride (2) at 800 ° C. in a tubular furnace for 1 hour while flowing argon gas containing 1 vol% of oxygen gas. 1.09 g of nitrous oxide (hereinafter also referred to as "catalyst (2)") was obtained.

Table 1 shows the results of elemental analysis of the obtained catalyst (2).

The powder X-ray diffraction spectrum of the catalyst (2) is shown in FIG. Seven diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 2 was obtained in the same manner as in Example 1 except that the catalyst (2) was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 2 was used.

40 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 2 produced in Example 2 had an oxygen reduction initiation potential of 0.72 V (vs. NHE) and had a high oxygen reduction ability.

[Example 3]

1. Preparation of Catalyst

Tin (20 mol%) and niobium were prepared in the same manner as in Example 1 except that 4.00 g ( ₃₂ mmol) of niobium (IV) (NbO ₂ ) and 1.21 g (8 mmol) of tin (IV) (SnO ₂ ) were used. 4.23 g of carbonitride (3) containing was prepared, and 1.09 g of carbonitride oxide (hereinafter also referred to as "catalyst (3)") containing tin (20 mol%) and niobium was prepared from 1.02 g of the carbonitride (3). It was. Table 1 shows the results of elemental analysis of the obtained catalyst (3).

The powder X-ray diffraction spectrum of the catalyst (3) is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 3 was obtained in the same manner as in Example 1 except that the catalyst (3) was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 3 was used.

41 shows a current-potential curve obtained by the above measurement.

The fuel cell electrode 3 produced in Example 3 has an oxygen reduction initiation potential of 0.65 V (vs. NHE) and has a high oxygen reduction ability.

Example 4

1. Preparation of Catalyst

Indium (0.4 mol%) in the same manner as in Example 1, except that 55 mg (0.2 mmol) of indium (III) oxide (In ₂ O ₃ ) was used instead of 60 mg (0.4 mmol) of tin oxide (IV) (SnO ₂ ). And 4.23 g of niobium-containing carbonitride (4), which is 1.02 g of carbonitride (4), and carbonitride oxide containing indium (0.4 mol%) and niobium (hereinafter referred to as "catalyst (4)") 1.10 g was prepared.

The powder X-ray diffraction spectrum of the catalyst (4) is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

The fuel cell electrode 4 was obtained like Example 1 except having used the said catalyst (4).

3. Evaluation of Oxygen Reduction Capacity

Catalytic capacity (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 4 was used.

42 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 4 produced in Example 4 had an oxygen reduction initiation potential of 0.80 V (vs. NHE) and had high oxygen reduction ability.

[Example 5]

1. Preparation of Catalyst

Change the amount of niobium (IV) (NbO ₂ ) from 4.95g (39.6mmol) to 4.75g (38mmol) and replace indium (III) (III) (0.4) ol instead of 60mg (0.4mmol) tin (IV) (SnO ₂ ) In ₂ O ₃ ) 3.94 g of carbonitride (5) containing indium (5 mol%) and niobium were prepared in the same manner as in Example 1 except that 278 mg ( ₂ mmol) was used, and the carbonitride (5) 1.02 In g, 1.10 g of carbonitride oxide (hereinafter also referred to as "catalyst (5)") containing indium (5 mol%) and niobium was prepared. Table 1 shows the results of elemental analysis of the obtained catalyst (5).

The powder X-ray diffraction spectrum of the catalyst (5) is shown in FIG. Five diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

The fuel cell electrode 5 was obtained like Example 1 except having used the said catalyst (5).

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 5 was used.

43 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 5 produced in Example 5 had an oxygen reduction initiation potential of 0.80 V (vs. NHE) and had high oxygen reduction ability.

[Example 6]

1. Preparation of Catalyst

Change the amount of niobium (IV) (NbO ₂ ) from 4.95g (39.6mmol) to 4.00g (32mmol) and replace indium oxide (III) (IV) (SnO ₂ ) 60mg (0.4mmol) 3.34 g of carbonitride (6) containing indium (20 mol%) and niobium were produced in the same manner as in Example 1 except that 1.11 g (8 mmol) of In ₂ O ₃ ) was used, and the carbonitride (6) 1.11 g of carbonitride oxide (hereinafter also referred to as "catalyst (6)") containing indium (20 mol%) and niobium was prepared at 1.02 g. Table 1 shows the results of elemental analysis of the obtained catalyst (6).

The powder X-ray diffraction spectrum of the catalyst (6) is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

The fuel cell electrode 6 was obtained like Example 1 except having used the said catalyst (6).

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 6 was used.

44 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 6 produced in Example 6 had an oxygen reduction initiation potential of 0.80 V (vs. NHE) and had high oxygen reduction ability.

[Example 7]

1. Preparation of Catalyst

4.96 g (42.5 mmol) of niobium carbide (NbC), 0.60 g (2.5 mmol) of indium oxide (In ₂ O ₃ ), and 0.27 g (2.5 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 5.12 g of carbonitrides (7) containing indium and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1400 degreeC for 3 hours in nitrogen atmosphere. The carbonitride (7) of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 1, 1.11 g of carbonitride oxide (hereinafter also referred to as "catalyst (7)") containing indium and niobium was produced with 1.02 g of the carbonitride (7).

The powder X-ray diffraction spectrum of the catalyst (7) is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 7 was obtained in the same manner as in Example 1 except that the catalyst (7) was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 7 was used.

45 shows a current-potential curve obtained by the above measurement.

The fuel cell electrode 7 produced in Example 7 had an oxygen reduction initiation potential of 0.82 V (vs. NHE) and had high oxygen reduction ability.

[Example 8]

1. Preparation of Catalyst

4.96 g (42.5 mmol) of niobium carbide (NbC), 1.11 g (2.5 mmol) of tantalum oxide (Ta ₂ O ₅ ), 0.27 g (2.5 mmol) of niobium nitride (NbN) were mixed well, and the mixture was heated to 1500 ° C. 5.94 g of carbonitrides (8) containing tantalum and niobium were obtained by heat-processing in nitrogen atmosphere for time. The carbonitride (8) of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 1, 1.11 g of carbonitride oxide (hereinafter also referred to as "catalyst (8)") containing tantalum and niobium was produced with 1.02 g of the above-mentioned carbonitride (8).

The powder X-ray diffraction spectrum of the catalyst (8) is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

The fuel cell electrode 8 was obtained like Example 1 except having used the said catalyst (8).

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 8 was used.

46 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 8 produced in Example 8 had an oxygen reduction initiation potential of 0.83 V (vs. NHE) and had high oxygen reduction ability.

[Example 9]

1. Preparation of Catalyst

Niobium carbide (NbC) 4.96 g (42.5 mmol), niobium oxide (NbO ₂ ) 0.31 g (2.5 mmol), platinum oxide (PtO ₂ ) 0.57 g (2.5 mmol), niobium nitride (NbN) 0.27 g (2.5 mmol) The mixture was mixed well, and the mixture was heat-treated at 1600 ° C. for 3 hours in a nitrogen atmosphere to obtain 5.87 g of carbonitride (9) containing platinum and niobium. The carbonitride (9) of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 1, 1.10 g of carbonitride oxide (hereinafter also referred to as "catalyst (9)") containing platinum and niobium was produced from 1.02 g of the carbonitride (9).

The powder X-ray diffraction spectrum of the catalyst (9) is shown in FIG. Six diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 9 was obtained in the same manner as in Example 1 except that the catalyst (9) was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 9 was used.

47 shows the current-potential curve obtained by the above measurement.

It was found that the fuel cell electrode 9 produced in Example 9 had an oxygen reduction initiation potential of 0.90 V (vs. NHE) and had high oxygen reduction ability.

[Example 10]

1. Preparation of Catalyst

5.05 g (40 mmol) of niobium (IV) (NbO ₂ ) is mixed well with 20 g of 20% Pt carbon (Pt: 1.6 mmol), and the mixture is mixed at 1600 ° C. for 1 hour in a nitrogen atmosphere. By heat treatment, 4.47 g of carbonitride (10) containing platinum and niobium were obtained. The carbonitride 10 of the sintered compact was grind | pulverized with the ball mill.

Thereafter, in the same manner as in Example 1, 1.10 g of carbonitride oxide (hereinafter also referred to as "catalyst 10") containing platinum and niobium was produced from 1.02 g of the carbonitride (10).

The powder X-ray diffraction spectrum of the catalyst (10) is shown in FIG. Five diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

The fuel cell electrode 10 was obtained like Example 1 except having used the said catalyst (10).

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 10 was used.

48 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 10 produced in Example 10 had an oxygen reduction initiation potential of 0.95 V (vs. NHE) and had high oxygen reduction ability.

[Example 11]

1. Preparation of Catalyst

Niobium carbide (NbC) 4.96 g (42.5 mmol), indium tin oxide (In ₂ O ₂ -SnO ₂ ) (ITO) (powder made by Shokubai Kasei Kogyo Co., Ltd.) 0.69 g (2.5 mmol), niobium nitride (NbN) 0.27 g (2.5 mmol) was thoroughly ground and mixed. 5.94 g of carbonitrides (11) containing indium, tin, and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1400 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 11 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 1, 1.10 g of carbonitride oxide (hereinafter also referred to as "catalyst 11") containing indium, tin, and niobium was produced from 1.02 g of the carbonitride (11).

The powder X-ray diffraction spectrum of the catalyst (11) is shown in FIG. Five diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 11 was obtained in the same manner as in Example 1 except that the catalyst 11 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 11 was used.

49 shows a current-potential curve obtained by the above measurement.

The fuel cell electrode 11 produced in Example 11 had an oxygen reduction initiation potential of 0.85 V (vs. NHE) and had a high oxygen reduction ability.

Comparative Example 1

1. Preparation of Catalyst

4.96 g (81 mmol) of niobium carbide (NbC), 1.25 g (10 mmol) of niobium oxide (NbO ₂ ), and 0.54 g (5 mmol) of niobium nitride (NbN) were mixed well and heat-treated at 1500 ° C. for 3 hours in a nitrogen atmosphere. Thus, 2.70 g of niobium carbonitride (hereinafter also referred to as "catalyst 12") of the sintered compact was obtained. Since it became a sintered compact, it grind | pulverized with the ball mill.

Table 1 shows the results of elemental analysis of the pulverized catalyst (12).

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 12 was obtained in the same manner as in Example 1 except that the obtained niobium carbonitride was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 12 was used.

50 shows the current-potential curve obtained by the above measurement.

It was found that the fuel cell electrode 12 produced in Comparative Example 1 had an oxygen reduction initiation potential of 0.45 V (vs. NHE) and a low oxygen reduction capacity.

[Example 12]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.40 g (2.5 mmol) of ferric oxide (Fe ₂ O ₃ ), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 11.19 g of carbonitrides (13) containing iron and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 13 of the sintered compact was grind | pulverized with the ball mill. 1.00 g of the obtained carbonitride (13) was subjected to heat treatment at 900 ° C. for 6 hours in a tubular furnace while flowing nitrogen gas containing 1% by volume of oxygen gas and 0.8% by volume of hydrogen gas, thereby producing iron (5 mol%). And 1.24 g of carbonitride oxide (hereinafter also referred to as "catalyst 13") containing niobium. Table 1 shows the results of elemental analysis of the obtained catalyst (13).

The powder X-ray diffraction spectrum of the catalyst (13) is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

The fuel cell electrode 13 was obtained like Example 1 except having used the said catalyst (13).

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 13 was used.

51 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 13 produced in Example 12 had an oxygen reduction initiation potential of 0.90 V (vs. NHE) and had high oxygen reduction ability.

[Example 13]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.36 g (5 mmol) of manganese oxide (MnO), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 10.93 g of carbonitrides (14) containing manganese and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 14 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.33 g of carbonitride oxide (hereinafter also referred to as "catalyst 14") containing manganese and niobium was produced from 1.04 g of the carbonitride (14). Table 1 shows the results of elemental analysis of the obtained catalyst (14).

The powder X-ray diffraction spectrum of the catalyst 14 is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °. When a powder X-ray diffraction spectrum of the catalyst of the spectrum search 14, the peak of the Nb ₁₂ O ₂₉ origin was observed as shown in FIG.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 14 was obtained in the same manner as in Example 1 except that the catalyst 14 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 14 was used.

52 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 14 produced in Example 13 had an oxygen reduction initiation potential of 0.85 V (vs. NHE) and had high oxygen reduction ability.

Example 14

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.86 g (5 mmol) of cerium oxide (CeO ₂ ), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 11.69 g of carbonitrides (15) containing cerium and niobium were obtained by heat-treating this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 15 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.31 g of carbonitride oxide (hereinafter also referred to as "catalyst 15") containing cerium and niobium was produced from 1.03 g of the carbonitride (15). Table 1 shows the results of elemental analysis of the obtained catalyst (15).

The powder X-ray diffraction spectrum of the catalyst (15) is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °. When a powder X-ray diffraction spectrum of the catalyst of the spectrum search 15, the peak of the Nb ₁₂ O ₂₉ origin was observed as shown in Fig.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 15 was obtained in the same manner as in Example 1 except that the catalyst 15 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic capacity (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 15 was used.

53 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 15 produced in Example 14 had an oxygen reduction initiation potential of 0.86 V (vs. NHE) and had high oxygen reduction ability.

Example 15

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.38 g (2.5 mmol) of chromium oxide (Cr ₂ O ₃ ), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 11.17 g of carbonitrides (16) containing chromium and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 16 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.20 g of carbonitride oxide (hereinafter also referred to as "catalyst 16") containing chromium and niobium was produced with 0.97 g of the carbonitride (16). Table 1 shows the results of elemental analysis of the obtained catalyst (16).

The powder X-ray diffraction spectrum of the catalyst 16 is shown in FIG. 17. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °. When a powder X-ray diffraction spectrum of the catalyst of the spectrum search 16, the peak of the Nb ₁₂ O ₂₉ origin was observed as shown in Fig.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 16 was obtained in the same manner as in Example 1 except that the catalyst 16 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 16 was used.

54 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 16 produced in Example 15 had an oxygen reduction initiation potential of 0.85 V (vs. NHE) and had high oxygen reduction ability.

[Example 16]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.87 g (5 mmol) of iron acetate (C ₄ H ₆ O ₄ Fe), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 10.89 g of carbonitrides (17) containing iron and niobium were obtained by heat-treating this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 17 of the sintered compact was grind | pulverized with the ball mill. After this, in the same manner as in Example 12, 1.34 g of the carbonitride (17) containing 1.34 g of carbonitride oxide (hereinafter also referred to as "catalyst 17") containing iron and niobium was produced. Table 1 shows the results of elemental analysis of the obtained catalyst (17).

The powder X-ray diffraction spectrum of the catalyst (17) is shown in FIG. Six diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °. When a powder X-ray diffraction spectrum of the catalyst of the spectrum search 17, the peak of the Nb ₁₂ O ₂₉ origin was observed as shown in Fig.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 17 was obtained in the same manner as in Example 1 except that the catalyst 17 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 17 was used.

55 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 17 produced in Example 16 had an oxygen reduction initiation potential of 0.90 V (vs. NHE) and had high oxygen reduction ability.

Example 17

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 1.29 g (5 mmol) of cobalt acetylacetone complex (C ₁₀ H ₁₄ O ₄ Co), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 10.94 g of carbonitrides (18) containing cobalt and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 18 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.35 g of carbonitride oxide (hereinafter also referred to as "catalyst 18") containing 1.05 g of the carbonitride (18) was produced. Table 1 shows the results of elemental analysis of the obtained catalyst (18).

The powder X-ray diffraction spectrum of the catalyst (18) is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °. When a powder X-ray diffraction spectrum of the catalyst of the spectrum search 18, the peak of the Nb ₁₂ O ₂₉ origin was observed as shown in Fig. 22.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 18 was obtained in the same manner as in Example 1 except that the catalyst 18 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 18 was used.

56 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 18 produced in Example 17 had an oxygen reduction initiation potential of 0.87 V (vs. NHE) and had high oxygen reduction ability.

[Example 18]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC) and 5.14 g (48 mmol) of niobium nitride (NbN) were mixed, and 0.203 g (0.5 mmol) of tetrachlorogold acid (HAuCl ₄ nH ₂ O) dissolved in 1 ml of ethanol was added. The mixture was ground and mixed sufficiently. 11.33 g of carbonitrides (19) containing gold and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 19 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.25 g of carbonitride oxide (hereinafter also referred to as "catalyst 19") containing gold and niobium was produced from 1.02 g of the carbonitride (19). Table 1 shows the results of elemental analysis of the obtained catalyst (19).

The powder X-ray diffraction spectrum of the catalyst (19) is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 19 was obtained in the same manner as in Example 1 except that the catalyst 19 was used.

3. Evaluation of Oxygen Reduction Capacity

Except having used the said fuel cell electrode 19, it carried out similarly to Example 1, and evaluated catalytic performance (oxygen reduction ability).

57 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 19 produced in Example 18 had an oxygen reduction initiation potential of 0.90 V (vs. NHE) and had high oxygen reduction ability.

[Example 19]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.835 g (5 mmol) of silver acetate (C ₂ H ₃ O ₂ Ag), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 10.82 g of carbonitrides 20 containing silver and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 20 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.27 g of carbonitride oxide (hereinafter also referred to as "catalyst 20") containing silver and niobium was produced from 0.98 g of the carbonitride (20). Table 1 shows the results of elemental analysis of the obtained catalyst (20).

The powder X-ray diffraction spectrum of the catalyst 20 is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 20 was obtained in the same manner as in Example 1 except that the catalyst 20 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 20 was used.

58 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 20 produced in Example 19 had an oxygen reduction initiation potential of 0.88 V (vs. NHE) and had high oxygen reduction ability.

[Example 20]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.61 g (5 mmol) of palladium oxide (PdO), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 11.63 g of carbonitrides (21) containing palladium and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 21 of the sintered compact was ground by the ball mill. Thereafter, in the same manner as in Example 12, 1.26 g of carbonitride oxide (hereinafter also referred to as "catalyst 21") containing palladium and niobium was produced with 0.99 g of the carbonitride (21). Table 1 shows the results of elemental analysis of the obtained catalyst (21).

The powder X-ray diffraction spectrum of the catalyst 21 is shown in FIG. 25, and the enlarged view of the diffraction angle 2 (theta) = 30 degrees-45 degrees in this powder X-ray diffraction spectrum is shown in FIG. Four diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 21 was obtained in the same manner as in Example 1 except that the catalyst 21 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 21 was used.

59 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 21 produced in Example 20 has an oxygen reduction initiation potential of 0.88 V (vs. NHE), and has a high oxygen reduction ability.

Example 21

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 1.12 g (5 mmol) of iridium oxide (IrO ₂ ), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 11.29 g of carbonitrides (22) containing iridium and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 22 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.27 g of carbonitride oxide (hereinafter also referred to as "catalyst 22") containing iridium and niobium was produced with 1.01 g of the above-mentioned carbonitride (22). Table 1 shows the results of elemental analysis of the obtained catalyst (22).

The powder X-ray diffraction spectrum of the catalyst 22 is shown in FIG. 27, and the enlarged view of the diffraction angle 2 (theta) = 30 degrees-45 degrees in this powder X-ray diffraction spectrum is shown in FIG. Five diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 22 was obtained in the same manner as in Example 1 except that the catalyst 22 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 22 was used.

60 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 22 produced in Example 21 had an oxygen reduction initiation potential of 0.88 V (vs. NHE) and had high oxygen reduction ability.

[Example 22]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.67 g (5 mmol) of ruthenium oxide (RuO ₂ ), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. 11.29 g of carbonitrides (23) containing ruthenium and niobium were obtained by heat-processing this mixed powder in a tubular furnace at 1600 degreeC for 3 hours in nitrogen atmosphere. The carbonitride 23 of the sintered compact was grind | pulverized with the ball mill. Thereafter, in the same manner as in Example 12, 1.29 g of carbonitride oxide (hereinafter also referred to as "catalyst 23") containing ruthenium and niobium was produced from 1.02 g of the carbonitride (23). Table 1 shows the results of elemental analysis of the obtained catalyst (23).

The powder X-ray diffraction spectrum of the catalyst 23 is shown in FIG. 29, and the enlarged view of the diffraction angle 2 (theta) = 30 degrees-45 degrees in this powder X-ray diffraction spectrum is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 23 was obtained in the same manner as in Example 1 except that the catalyst 23 was used.

3. Evaluation of Oxygen Reduction Capacity

Except having used the said fuel cell electrode 23, it carried out similarly to Example 1, and evaluated catalytic performance (oxygen reduction ability).

61 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 23 produced in Example 22 had an oxygen reduction initiation potential of 0.88 V (vs. NHE) and had high oxygen reduction ability.

[Example 23]

1. Preparation of Catalyst

5.17 g (49 mmol) of niobium carbide (NbC), 0.30 g (0.9 mmol) of lanthanum oxide (La ₂ O ₃ ), and 4.52 g (42 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. The mixed powder was heat-treated in a tubular furnace at 1600 ° C. for 3 hours in a nitrogen atmosphere to obtain carbonitride (24) containing niobium and lanthanum.

Next, in the rotary kiln, 0.5 g of the obtained carbonitride (24) was flowed at 950 ° C for 8 hours while flowing an equal amount of argon gas containing 1% by volume of oxygen gas and nitrogen gas containing 4% by volume of hydrogen gas. By heat treatment, carbonitride oxide containing niobium and lanthanum (hereinafter also referred to as "catalyst 24") was produced.

The powder X-ray diffraction spectrum of the catalyst 24 is shown in FIG. 31, and the enlarged view of the diffraction angle 2 (theta) = 30 degrees-45 degrees in this powder X-ray diffraction spectrum is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 24 was obtained in the same manner as in Example 1 except that the catalyst 24 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 24 was used.

62 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 24 produced in Example 23 had an oxygen reduction initiation potential of 0.88 V (vs. NHE) and had a high oxygen reduction ability.

Example 24

1. Preparation of Catalyst

5.17 g (49 mmol) of niobium carbide (NbC), 0.31 g (0.3 mmol) of praseodymium oxide (Pr ₆ O ₁₁ ), and 4.52 g (42 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. The mixed powder was heat-treated in a tubular furnace at 1600 ° C. for 3 hours in a nitrogen atmosphere to obtain carbonitride (25) containing niobium and praseodymium.

Next, in the rotary kiln, 0.5 g of the obtained carbonitride (25) was flowed at 950 ° C for 8 hours while flowing an equal amount of argon gas containing 1% by volume of oxygen gas and nitrogen gas containing 4% by volume of hydrogen gas. By heat treatment, carbonitride oxide containing niobium and praseodymium (hereinafter also referred to as "catalyst 25") was produced.

The powder X-ray diffraction spectrum of the catalyst 25 is shown in FIG. 33, and the enlarged view of the diffraction angle 2 (theta) = 30 degrees-45 degrees in this powder X-ray diffraction spectrum is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 25 was obtained in the same manner as in Example 1 except that the catalyst 25 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic capacity (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 25 was used.

63 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 25 produced in Example 24 had an oxygen reduction initiation potential of 0.85 V (vs. NHE) and had high oxygen reduction ability.

[Example 25]

1. Preparation of Catalyst

5.17 g (49 mmol) of niobium carbide (NbC), 0.31 g (0.9 mmol) of neodymium oxide (Nd ₂ O ₃ ), and 4.51 g (42 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. This mixed powder was heat-treated in a tubular furnace at 1600 ° C. for 3 hours in a nitrogen atmosphere to obtain carbonitride (26) containing niobium and neodymium.

Next, in the rotary kiln, 0.5 g of carbonitride (26) obtained was flowed at 950 ° C. for 8 hours while flowing an equal amount of argon gas containing 1% by volume of oxygen gas and nitrogen gas containing 4% by volume of hydrogen gas. By heat treatment, carbonitride oxide containing niobium and neodymium (hereinafter also referred to as "catalyst 26") was produced.

The powder X-ray diffraction spectrum of the catalyst 26 is shown in FIG. 35, and the enlarged view of the diffraction angle 2 (theta) = 30 degrees-45 degrees in this powder X-ray diffraction spectrum is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 26 was obtained in the same manner as in Example 1 except that the catalyst 26 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 26 was used.

64 shows the current-potential curve obtained by the above measurement.

The fuel cell electrode 26 produced in Example 25 had an oxygen reduction initiation potential of 0.85 V (vs. NHE) and had high oxygen reduction ability.

Example 26

1. Preparation of Catalyst

5.17 g (49 mmol) of niobium carbide (NbC), 0.32 g (0.9 mmol) of samarium oxide (Sm ₂ O ₃ ), and 4.51 g (42 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. This mixed powder was heat-treated in a tubular furnace at 1600 ° C. for 3 hours in a nitrogen atmosphere to obtain carbonitride (27) containing niobium and samarium.

Next, in the rotary kiln, 0.5 g of the carbonitride (27) obtained was flowed at 950 ° C for 8 hours while flowing an equal amount of argon gas containing 1% by volume of oxygen gas and nitrogen gas containing 4% by volume of hydrogen gas. By heat treatment, carbonitride oxide (hereinafter also referred to as "catalyst 27") containing niobium and samarium was produced.

The powder X-ray diffraction spectrum of the catalyst 27 is shown in FIG. 37, and the enlarged view of the diffraction angle 2 (theta) = 30 degrees-45 degrees in this powder X-ray diffraction spectrum is shown in FIG. Three diffraction line peaks were observed between the diffraction angles 2θ = 33 ° to 43 °.

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 27 was obtained in the same manner as in Example 1 except that the catalyst 27 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 27 was used.

65 shows the current-potential curve obtained by this measurement.

The fuel cell electrode 27 produced in Example 26 had an oxygen reduction initiation potential of 0.90 V (vs. NHE) and had high oxygen reduction ability.

Comparative Example 2

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.40 g (2.5 mmol) of ferric oxide (Fe ₂ O ₃ ), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. This mixed powder was heat-treated in a tubular furnace at 1600 ° C. for 3 hours in a nitrogen atmosphere, whereby 11.19 g of carbonitride containing iron and niobium (hereinafter also referred to as “catalyst 28”) was obtained. The catalyst 28 of the sintered compact was grind | pulverized with the ball mill.

Table 1 shows the results of elemental analysis of the pulverized catalyst (28).

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 28 was obtained in the same manner as in Example 1 except that the catalyst 28 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic performance (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 28 was used.

66 shows a current-potential curve obtained by the above measurement.

It was found that the fuel cell electrode 28 produced in Comparative Example 1 had an oxygen reduction initiation potential of 0.50 V (vs. NHE) and low oxygen reduction ability.

[Comparative Example 3]

1. Preparation of Catalyst

5.88 g (56 mmol) of niobium carbide (NbC), 0.86 g (5 mmol) of cerium oxide (CeO ₂ ), and 5.14 g (48 mmol) of niobium nitride (NbN) were sufficiently ground and mixed. This mixed powder was heat-treated in a tubular furnace at 1600 ° C. for 3 hours in a nitrogen atmosphere, whereby 11.69 g of carbonitride containing cerium and niobium (hereinafter also referred to as “catalyst 29”) was obtained. The catalyst 29 of the sintered compact was crushed with a ball mill.

Table 1 shows the results of elemental analysis of the pulverized catalyst (29).

2. Manufacturing of Electrode for Fuel Cell

A fuel cell electrode 29 was obtained in the same manner as in Example 1 except that the catalyst 29 was used.

3. Evaluation of Oxygen Reduction Capacity

Catalytic capacity (oxygen reduction ability) was evaluated in the same manner as in Example 1 except that the fuel cell electrode 29 was used.

67 shows the current-potential curve obtained by the above measurement.

It was found that the fuel cell electrode 29 produced in Comparative Example 1 had an oxygen reduction initiation potential of 0.45 V (vs. NHE) and low oxygen reduction ability.

Industrial Applicability

Since the catalyst of the present invention does not corrode in an acidic electrolyte or a high potential, has excellent durability, and has a high oxygen reduction ability, the catalyst can be used in a fuel cell catalyst layer, an electrode, an electrode assembly or a fuel cell.

Claims (21)

At least one metal selected from the group consisting of tin, indium, tantalum, platinum, iron, manganese, cerium, chromium, cobalt, gold, silver, palladium, iridium, ruthenium, lanthanum, praseodymium, neodymium and samarium (hereinafter referred to as `` metal M Or "M") and a metal carbonitride containing niobium. The method of claim 1, wherein the composition formula of the carbonaceous oxide is Nb _a M _b C _x N _y O _z (where a, b, x, y, z represents the ratio of the number of atoms, 0.01≤a <1, 0 <B ≦ 0.99, 0.01 ≦ x ≦ 2, 0.01 ≦ y ≦ 2, 0.01 ≦ z ≦ 3, a + b = 1, and x + y + z ≦ 5). The diffraction line peak according to claim 1 or 2, wherein the metal carbonitride oxide is measured by powder X-ray diffraction (Cu-Kα-ray) and has two or more diffraction line peaks between diffraction angles 2θ = 33 ° to 43 °. Oxygen reduction catalyst characterized in that observed. The metal carbonitride according to claim 1 or 2, wherein the metal carbonitride is a mixture containing several phases, and when the metal carbonitride is measured by powder X-ray diffraction (Cu-Kα), Nb ₁₂ O ₂₉ Oxygen reduction catalyst characterized in that the peak derived from is observed. Oxide, oxide of at least one metal M selected from the group consisting of tin, indium, tantalum, platinum, iron, manganese, cerium, chromium, cobalt, gold, silver, palladium, iridium, ruthenium, lanthanum, praseodymium, neodymium and samarium Step (ia) of obtaining a metal carbonitride by heat-treating the mixture of niobium and carbon in nitrogen atmosphere or an inert gas containing nitrogen, and obtaining the catalyst containing a metal carbonitride by heat-processing the said metal carbonitride in oxygen containing inert gas. A process for producing a catalyst comprising metal carbonitride, comprising step (ii). Oxide, carbonization of at least one metal M selected from the group consisting of tin, indium, tantalum, platinum, iron, manganese, cerium, chromium, cobalt, gold, silver, palladium, iridium, ruthenium, lanthanum, praseodymium, neodymium and samarium (Ii) obtaining a metal carbonitride by heat-treating a mixture of niobium and niobium nitride in an inert gas; and (ii) obtaining a catalyst containing metal carbonitride by heat treating the metal carbonitride in an oxygen-containing inert gas. Method for producing a catalyst comprising a metal carbonitride, characterized in that. Oxide, carbonization of at least one metal M selected from the group consisting of tin, indium, tantalum, platinum, iron, manganese, cerium, chromium, cobalt, gold, silver, palladium, iridium, ruthenium, lanthanum, praseodymium, neodymium and samarium (Ic) obtaining a metal carbonitride by heat-treating a mixture of niobium, niobium nitride, and niobium oxide in an inert gas; and obtaining a catalyst containing metal carbonitride by heat-treating the metal carbonitride in an oxygen-containing inert gas (ii). Method for producing a catalyst comprising a metal carbonitride comprising a). Compounds containing at least one metal M selected from the group consisting of tin, indium, tantalum, platinum, iron, manganese, cerium, chromium, cobalt, gold, silver, palladium, iridium, ruthenium, lanthanum, praseodymium, neodymium and samarium And (i) obtaining a metal carbonitride by heat-treating a mixture of niobium carbide and niobium nitride in an inert gas, and obtaining a catalyst containing metal carbonitride by heat-treating the metal carbonitride in an oxygen-containing inert gas. Method for producing a catalyst comprising a metal carbonitride comprising a. The method for producing a catalyst containing metal carbonitride according to claim 5, wherein the heat treatment temperature in the step (ia) is in the range of 600 to 1800 ° C. The method for producing a catalyst containing metal carbonitride according to claim 6, wherein the heat treatment temperature in the step (ib) is in the range of 600 to 1800 ° C. The process for producing a catalyst comprising a metal carbonitride according to claim 7, wherein the heat treatment temperature in the step (ic) is in the range of 600 to 1800 ° C. The method for producing a catalyst comprising a metal carbonitride according to claim 8, wherein the heat treatment temperature in the step (id) is in the range of 600 to 1800 ° C. The method for producing a catalyst comprising a metal carbonitride according to any one of claims 5 to 12, wherein the heat treatment temperature in the step (ii) is in the range of 400 to 1400 ° C. The production of a catalyst containing metal carbonitride according to any one of claims 5 to 12, wherein the oxygen gas concentration in the inert gas in the step (ii) is in the range of 0.1 to 10% by volume. Way. The catalyst according to any one of claims 5 to 12, wherein the inert gas in the step (ii) contains hydrogen gas in a range of 5% by volume or less. Manufacturing method. A catalyst layer for a fuel cell, comprising the oxygen reduction catalyst according to claim 1. The catalyst layer for a fuel cell according to claim 16, further comprising electron conductive particles. An electrode having a fuel cell catalyst layer and a porous support layer, wherein the fuel cell catalyst layer is the fuel cell catalyst layer according to claim 16. A membrane electrode assembly having a cathode, an anode, and an electrolyte membrane disposed between the cathode and the anode, wherein the cathode, the anode, or both are electrodes according to claim 18. A membrane electrode assembly. A fuel cell comprising the membrane electrode assembly according to claim 19. A polymer electrolyte fuel cell comprising the membrane electrode assembly according to claim 19.

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